math help

What is 20/64 + 9/11?

What is 20/64 + 9/11?

This is how to add

20
64
+
9
11

Step 1

We can't add two fractions with different denominators (the bottom number). So you need to get a common denominator - both bottom numbers need to match. To do this, you'll multiply the denominators times each other... but the numerators have to change, too. They get multiplied by the other term's denominator.

So we multiply 20 by 11, and get 220, then we multiply 64 by 11 and get 704.

20/64 times 11

Do the same for the second term. We multiply 9 by 64, and get 576, then multiply 64 by 11 and get 704.

9/11 times 64

So now our fractions look like this:

220
704
+
576
704

Step 2

Since our denominators match, we can add the numerators.

220 + 576 = 796

So the answer is:

796
704

Step 3

Last of all, we need to simplify the fraction, if possible. Can it be reduced to a simpler fraction?

To find out, we try dividing it by 2...

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

796
704
÷ 2 =
398
352

So far so good... let's try to divide by that number again.

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

398
352
÷ 2 =
199
176

So far so good... let's try to divide by that number again.

No good. So next you try the next prime number, which is 3...

No good. So next you try the next prime number, which is 5...

No good. So next you try the next prime number, which is 7...

No good. So next you try the next prime number, which is 11...

No good. So next you try the next prime number, which is 13...

No good. So next you try the next prime number, which is 17...

No good. So next you try the next prime number, which is 19...

No good. So next you try the next prime number, which is 23...

No good. So next you try the next prime number, which is 29...

No good. So next you try the next prime number, which is 31...

No good. So next you try the next prime number, which is 37...

No good. So next you try the next prime number, which is 41...

No good. So next you try the next prime number, which is 43...

No good. So next you try the next prime number, which is 47...

No good. So next you try the next prime number, which is 53...

No good. So next you try the next prime number, which is 59...

No good. So next you try the next prime number, which is 61...

No good. So next you try the next prime number, which is 67...

No good. So next you try the next prime number, which is 71...

No good. So next you try the next prime number, which is 73...

No good. So next you try the next prime number, which is 79...

No good. So next you try the next prime number, which is 83...

No good. So next you try the next prime number, which is 89...

No good. So next you try the next prime number, which is 97...

No good. So next you try the next prime number, which is 101...

No good. So next you try the next prime number, which is 103...

No good. So next you try the next prime number, which is 107...

No good. So next you try the next prime number, which is 109...

No good. So next you try the next prime number, which is 113...

No good. So next you try the next prime number, which is 127...

No good. So next you try the next prime number, which is 131...

No good. So next you try the next prime number, which is 137...

No good. So next you try the next prime number, which is 139...

No good. So next you try the next prime number, which is 149...

No good. So next you try the next prime number, which is 151...

No good. So next you try the next prime number, which is 157...

No good. So next you try the next prime number, which is 163...

No good. So next you try the next prime number, which is 167...

No good. So next you try the next prime number, which is 173...

No good. So next you try the next prime number, which is 179...

No good. 179 is larger than 176. So we're done reducing.

And we're done! Here's the final answer to 20/64 + 9/11

20
64
+
9
11
=
199
176
© 2014 Randy Tayler